A patient taking dextroamphetamine reports starting St. John’s Wort; what is the concern?

• A. I started taking St. John's Wort this week to help with my depression.
• B. I take it daily with no issues.
• C. I stopped using it years ago.
• D. It will always be safe with stimulants.

Answer: (A)

Starting St. John’s Wort while you’re taking a stimulant raises an interaction risk because St. John’s Wort has serotonergic activity and can affect how other brain chemicals are balanced. When combined with a stimulant like dextroamphetamine, there’s a higher chance of excessive monoamine effects, which can show up as agitation, rapid heart rate, high blood pressure, sweating, tremor, or even serotonin syndrome in more serious cases. The fact that this change happened this week makes it a red flag to review immediately with a clinician. While past or daily use without issues might seem less concerning, starting it recently is the key warning in this scenario. If any signs of worsening agitation, chest symptoms, or mental status changes occur, seek urgent evaluation.